feat: prefill template with empty JSON when creating new config

src/componets/FileChooser.tsx

@@ -19,6 +19,7 @@ export function FileChooser(props: { onSelected: (x: Config) => void }) {
   function handleNew(){
     let cfg = new Config();
     cfg.addEnvs([new Env(0, "DEFAULT", [])]);
+    cfg.addTemplate("{}");
     props.onSelected(cfg);
   }